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Corbett, W.J.

Paper Title Page
RPAT080 The SPEAR 3 Diagnostic Beamlines 4057
 
  • W.J. Corbett, C. Limborg-Deprey, W.Y. Mok, A. Ringwall
    SLAC, Menlo Park, California
 
  Funding: Work supported in part by DOE contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences.

SPEAR 3 is equipped with an x-ray pinhole camera and a visible/UV beam line to evaluate electron beam properties. The pinhole camera has a 30 x 25 micron Ta aperture and 60% image demagnification on a phosphor screen. The image is captured by a National Instruments frame-grabber on a remote computer with a parallel video signal for control room monitoring. The visible/UV beam line features a horizontal ± 0.3 mrad ‘cold finger’ to remove the x-ray core of the beam. The remaining visible/UV light is deflected 18 degrees onto an optical bench where it is focused via refractive Cassegrain optics. The beam is then split into parallel optics for gated- and streak camera measurements. This paper describes the experimental set up and preliminary measurements obtained with both systems.

 
RPAT081 Initial Scraper Measurements in SPEAR 3
 
  • W.J. Corbett, J.A. Safranek, A. Terebilo
    SLAC, Menlo Park, California
 
  Funding: Work supported by Department of Energy Contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences.

Horizontal and vertical scraper assemblies have been installed in a standard straight section of SPEAR 3 (beta-x=10.2 m, beta-y=4.8 m, epsx=18 nm-rad, 0.1% coupling). Each scraper has stepper motor accuracy and transductor resolution on the order of 1 micron and a MATLAB/EPICS interface to simplify data acquisition. In this paper we present initial scraper measurements and analysis of the results. Of particular importance are comparison of measured dynamic aperture and momentum acceptance with model and measurement of vertical acceptance for future beam lines.

 
FPAT077 An Accelerator Control Middle Layer Using Matlab 4009
 
  • G.J. Portmann
    LBNL, Berkeley, California
  • W.J. Corbett, A. Terebilo
    SLAC, Menlo Park, California
 
  Funding: U.S. Department of Energy under Contract No. DEAC03-76SF00098.

Matlab is a matrix manipulation language originally developed to be a convenient language for using the LINPACK and EISPACK libraries. What makes Matlab so appealing for accelerator physics is the combination of a matrix oriented programming language, an active workspace for system variables, powerful graphics capability, built-in math libraries, and platform independence. A number of software toolboxes for accelerators have been written in Matlab – the Accelerator Toolbox (AT) for machine simulations, LOCO for accelerator calibration, Matlab Channel Access Toolbox (MCA) for EPICS connections, and the Middle Layer. This paper will describe the MiddleLayer software toolbox that resides between the high-level control applications and the low-level accelerator control system. This software was a collaborative effort between ALS and Spear but was written to easily port. Five accelerators presently use this software – Spear, ALS, CLS, and the X-ray and VUV rings at Brookhaven. The Middle Layer functionality includes energy ramp, configuration control, global orbit correction, local beam steering, insertion device compensation, beam-based alignment, tune correction, response matrices, and script-based physics studies.